The continuous increase in demand for a better mobile communication service is encouraging research and industry to define new network design principles so that the future need on performance, capacity, and reliability can be met. For this reason, the Next Generation Mobile Networks (NGMN) alliance has envisioned the fifth generation of mobile communications (5G) with the purpose of reaching a much higher throughput, lower latency, ultra-high reliability, higher connectivity, and higher user mobility. This new upcoming release, however, is not only about the development of a new radio interface, but also to enable the operation in a highly heterogeneous environment. Such an environment is typically characterized by the presence of multi-layer networks, different types of access technologies, as well as a high number of small cells densely clustered together, thereby, giving a contiguous coverage. Furthermore, a 5G network should at the same time enable a high network availability and reliability as well as guarantee certain services for critical infrastructures.
The Self-Organizing Networks (SON) concept as known today, which basically allows base stations to automatically configure themselves, will be much further developed in 5G systems. Advanced SON techniques will not only apply to physical Network Elements (NEs), but will enable operators to, for instance, balance load in a multi-radio-access technology environment, and support traffic steering as well as dynamic spectrum allocation.
SON features may be designed to optimize the operation of the network, supervise the configuration and auto-connectivity of newly deployed NEs, and are also responsible for fault detection and resolution. Such a network is may be managed by a set of autonomous functions performing specific network management tasks. These SON functions may be designed as control loops which may monitor Performance Management (PM) and Fault Management (FM) data, and based on their goals, to adjust Configuration Management (CM) parameters.
Despite the development of SON, there may be a need to verify the performance impact of deployed CM changes after a reconfiguration has taken place. Therefore, the concept of SON verification has been developed. It may be seen as a special type of anomaly detection that implements a verification process. The outcome of the process is to accept deployed CM changes or to revert them to a previous stable state, which is also known as a CM undo request. The verification process itself operates in three phases. At first, it divides the network into verification areas according to the CM changes. Second, it runs an anomaly detection algorithm for each area. Third, it marks the changes for an undo that are most likely responsible for causing a degradation. Finally, it schedules CM undo requests for deployment.
Despite the process SON verification has made progress, it still has shortcomings in Long Term Evolution (LTE) as well the 5G release. In particular, a verification mechanism can experience difficulties in detecting anomalies and executing undo requests in case it is improperly timed. A too short observation may result in the generation of false positives which may hinder the active SON function from reaching the global performance optimum. For example, a function may induce a temporal performance decrease which can rolled back, i.e., the verification mechanism may interrupt the function while it tries to achieve its optimization goal.